What formula is used to calculate steel tube weight?

Weight = (π ÷ 4) × (OD² − ID²) × Length × Density. OD is the outer diameter and ID is the inner diameter. If you supply wall thickness instead, ID = OD − 2 × wall thickness. The result is multiplied by the steel density of 7850 kg/m³.

What is the standard density of steel used here?

This calculator uses 7850 kg/m³, the standard density for carbon steel and mild steel per most engineering standards (ASTM, EN, ISO).

What is the difference between a tube and a pipe?

Tubes are specified by outer diameter and wall thickness (or inner diameter) and are used in structural applications. Pipes are specified by nominal pipe size (NPS) and schedule, and are used primarily for fluid transport. The weight formula is the same for both.

How do I find the wall thickness of a tube?

Wall thickness is typically stamped on the tube or listed in its datasheet or mill certificate. You can also measure it directly with a caliper or micrometer on the tube end.

Can I enter inner diameter instead of wall thickness?

Yes. Use the toggle below the outer diameter input to switch between "Wall Thickness" mode and "Inner Diameter" mode.

What is linear weight (kg/m)?

Linear weight is the weight per meter of tube, useful for ordering by length. It equals the weight of a 1-meter section and is shown in the result breakdown.

Steel Tube Weight Calculator

Enter outer diameter, inner diameter (or wall thickness), and length to instantly calculate hollow steel tube weight in kg and lbs.

Tube Dimensions

Outer Diameter (OD)

Specify by: Wall Thickness Inner Diameter

Wall Thickness

Length

Formula Reference

W = (π / 4) × (OD² − ID²) × L × 7850

Where OD = outer diameter (m), ID = inner diameter (m), L = length (m), density = 7850 kg/m³ (carbon steel). If wall thickness t is given: ID = OD − 2t.

Enter tube dimensions on the left and click Calculate.

Common Carbon Steel CHS Sizes (7850 kg/m³)

OD (mm)	Wall (mm)	ID (mm)	kg/m
20	2.0	16.0	0.89
25	2.0	21.0	1.13
33.7	2.6	28.5	1.99
48.3	3.2	41.9	3.56
60.3	3.2	53.9	4.51
76.1	3.2	69.7	5.75
101.6	4.0	93.6	9.63
139.7	5.0	129.7	16.60

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Summary

Enter outer diameter, inner diameter (or wall thickness), and length to instantly calculate hollow steel tube weight in kg and lbs.

How it works

Enter the outer diameter (OD) of the tube.
Choose whether to specify the inner diameter directly or enter the wall thickness.
Enter the tube length.
Select your preferred units for each dimension.
Click Calculate — the tool applies Weight = π/4 × (OD² − ID²) × L × 7850 and displays results in kg and lbs.

Use cases

Estimating steel tube weight for structural and mechanical engineering projects.
Calculating shipping and freight weight for tube orders.
Preparing bill of materials for fabrication and construction.
Comparing tube weights across different wall thicknesses or outer diameters.
Checking load limits on tube supports and frames.
Verifying theoretical weight against mill certificates.
Frame and chassis weight calculations for automotive or industrial design.

Frequently Asked Questions

Last updated: 2026-09-19 · Reviewed by Nham Vu